Hermetic compressor discharge tube construction



Sept. 29, 1970 A L ETAL 3,531,222

HERMETIC COMPRESSOR DISCHARGE TUBE CONSTRUCTION Filed Aug. 8, 1968 2Sheets-Sheet 1 ATTORNEYS Sept. 29, 1970 RANDALL, ETAL 3,531,222

HERMETIC COMPRESSOR DISCHARGE TUBE CONSTRUCTION Filed Aug. 8, 1968 2Sheets-Sheet 2 44 j JO/I 4a--:- @2 0 L, /a 72 l 'I g /06 E INVENTORSATTORN EYS United States Patent Office Patented Sept. 29, 1970 3,531,222HERMETIC COMPRESSOR DISCHARGE TUBE CONSTRUCTION Freddie D. Randall andJames S. Utley, Tecumseh, Mich.,

assignors to Tecumseh Products Company, Tecumseh,

Mich., a corporation of Michigan Filed Aug. 8, 1968, Ser. No. 751,123Int. Cl. F04b 39/00; B611 21/00 U.S. Cl. 417-363 8 Claims ABSTRACT OFTHE DISCLOSURE A hermetic compressor in which a motor-compressor unit isresiliently suspended within a hermetic housing and a discharge tubeextends within the housing from the compressor outlet to a connectortube which extends through the wall of the housing to the exterior ofthe compressor. The connector tube is in part supported on the wall ofthe housing by a rigid connection. The connector tube is also supportedat a point spaced from the rigid connection and adjacent the dischargetube-connector tube interconnection by a bracket secured to the wall ofthe housing, and by a spring clip having legs inserted through thebracket and a center portion encircling the connector tube. The clip isself-retaining when mounted in assembled relation with the bracket andtube and also provides a resilient support for the tubes allowinglimited flexure at their interconnection to relieve stresses.

This invention relates to hermetic compressors and more particularly toa mounting arrangement and construction for the discharge and connectortubes of the compressor.

An object of the present invention is to provide a hermetic compressorhaving improved means for supporting the discharge and connector tubeswithin the compressor housing.

Another object is to provide a compressor of the above character whereinsaid support means comprises a very simple and inexpensive spring clipbracket arrangement which eliminates the usual silver solder connectionof the discharge connector tube to the bracket, thereby reducingmanufacturing and assembling costs, and which also distributes andrelieves the stresses of the flexing motion imparted to the dischargetube when the compressor vibrates in the housing, thereby reducing thepossibility of failure of the connector tube support.

Other objects as well as features and advantages of the presentinvention will become apparent from the following detailed descriptiontaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a side elevational view of a hermetic compressor incorporatingthe present invention, portions of the housing of the compressor beingbroken away to illustrate the motor-compressor unit mounted therein.

FIG. 2 is a horizontal sectional view taken on the line 2-2 of FIG. 1.

FIG. 3 is a fragmentary vertical section taken on the line 3-3 of FIG.2, but on an enlarged scale.

FIG. 4 is a fragmentary sectional view taken on the line 44 of FIG. 3.

FIG. 5 is a fragmentary side elevational view of the discharge andconnector tu-be joint illustrating the clip and bracket arrangement ofthe present invention.

FIG. 6 is a perspective view of the spring clip of the present inventionshown by itself, on a still larger scale.

Referring in more detail to the accompanying drawings, FIG. 1illustrates a compressor 10 which, as in conventional hermeticcompressor construction, comprises a housing 12 made up of lower halfshell casing 14 and an upper half shell casing 16 respectively havingcircumferentially extending radial flanges 18 and 20 which are Weldedtogether to hermetically seal the housing. A conventionalmotor-compressor unit generally designated 22 is resiliently mountedwithin and in spaced relation from housing 12 and comprises an electricmotor 24 which drives a twin cylinder piston compressor 26. Unit 22 isresiliently supported by three spaced coil springs 28, only one of whichis shown in FIG. 1, each mounted at its lower end on a bracket 30secured to casing 14 and at its upper end to the crankcase-frame casting32 of unit 22.

As is customary, compressor 26 has a discharge mufller 34 the outlet ofwhich is connected to the inlet end 36 (FIG. 2) of a discharge tube 38,usually made of welded steel tubing, adapted to conduct compressedrefrigerant gas from the mufller to an external connection via adischarge connector tube 40 (FIGS. 2-5). As best seen in FIGS. 1 and 2,tube 38 extends vertically upwardly from its inlet end 36 toward the topwall 39 of casing 16 and is then bent to an angle of about 90 so as toextend horizontally in an oblong loop 38a (FIG. 2) around the headspaceof casing 16 in spaced relation between casing 16 and the intakeseparator structure 42 mounted on the upper end of motor 24. Loop 38aterminates near the inlet riser 36, where tube 38 is again bent 90 toextend downwardly to form an outlet portion 44-the lower end 46 of Whichterminates approximately at the elevation of flanges 18 and 20 (FIG. 3).

Outlet end 44 of tube 38 has a telescopic interconnection with theupper, inlet end 48 of tube 40, which connection may consist of end 44sliding within end 48 (as shown in FIG. 3), or vice versa, the two ends44 and 48 being securely united and held in sealed relation at theirtelescopic interconnection by a silver soldered joint 50.

Connector tube 40 is generally L-shaped, inlet end 48 forming the longerriser of the L and the shorter riser 52 being disposed externally ofhousing 12 for suitable connection to the refrigeration equipment servedby compressor unit 10. The bight 54 of tube 40 extends through acircular opening '56 in the wall of casing 14 and carries a sealingflange 58 which abuts against the outer face of casing 14 and issecurely fixed thereto by a silver solder joint 60 so that opening 56 ishermetically sealed. If desired, riser 52 may be omitted and theexternal portion of tube 40 may extend horizontally or may have anyother suitable configuration to satisfy external hook up requirements.

In accordance with a principal feature of the present invention,discharge tube 38 and tube 40, considered as a two-piece rigidlyinterconnected assembly, are provided with additional semi-resilientsupport means disposed bet-Ween the rigid connection 60 and the rigidconnection of inlet end 36 with mufller 34. This additional supportmeans comprises a stamped sheet metal bracket 70 and a one piece springwire clip 72 best seen in FIGS. 3-6 inclusive.

Bracket 70 has a pair of oppositely extending end portions 74 and 76(FIGS. 4 and 5) formed to lie against the cylindrical inner surface 15of casing 14 and is sesured to this surface by spot welds 78 and 80(FIG. 5 As best seen in FIG. 4, bracket 70 is is corrugated to form acenter portion 82 having a convex surface 84 contacting surface 15 atthe center of the bracket and a concave surface 86 against which end 48of tube 40 nests. Portion 82 is flanked by a pair of crowns 88 and 90having concave inner surfaces 92 and 94 respectively which are spacedfrom surface 15. When the parts are arranged and constructed to thescale illustrated in the drawings, bracket 70 is preferably orientedwith its lengthwise dimension parallel to flange 18 of casing 14 withits upper edge approximately one quarter of an inch below the topsurface of flange 18. Crown 82 of bracket 70 is preferably disposed invertical alignment with the center line of aperture 56, with themid-point of the bracket being about three inches above the center ofaperture 56. Bracket 70 thus supports tube 40 with riser 48 thereofparallel and spaced from surface 15, the upper end edge 96 of riser 48being positioned about threeeighths of an inch above the upper surfaceof flange 18. It is to be understood that joint 50 may be disposedfurther above clip 72, for example by as much as about three inches inan arrangement scaled to the present disclosure without sacrificing theimproved results of the present invention.

Referring to FIG. 6, spring clip 72 preferably comprises a unitary pieceof spring steel piano wire having a diameter of about one-sixteenth ofan inch and a length of about 3.75 inches. This wire stock is bent toform a U-shaped bight portion 100 in the center of the wire which isadapted to extend horizontally (in the operative assembled position ofclip 72 as shown in FIG. 3) around tube 40 so as to embrace the side ofthe tube remote from bracket 70. Clip 72 has a pair of identical legs102 and 104 respectively dependant one from each of the ends of bight100. Each arm 102 and 104 has a straight vertical portion 106 slightlylonger than the vertical width dimension of bracket 70, a portion 108bent toward bight 100 so as to curve away from surface 15, and areversely bent portion 110 at the lower end of the leg which forms asmooth rounded protuberance adapted to bear slidably against surface 15in the stressed condition of spring clip 72 when assembled as describedhereinafter.

In the manufacture of compressor 10, connector tube 40 is installed incasing 14 prior to installation of motorcompressor unit 22 therein, tube40 being secured to casing 14 at joint 60 after bracket 70 has been spotwelded to casing 14. Preferably tube 40 is temporarily supported by clip72 and bracket 70 prior to and during the silver soldering operation atjoint 60. All that is required to so assemble tube 40 is to insert theriser end 48 from the exterior of the shell through aperture 56 and thenturn the tube upright so that riser 48 lies against the center portion82 of bracket 70. Clip 72 is then inserted on bracket 70 by placingbight 100 against tube 48 and, with feet 110 disposed one above and inalignment with each of the spaces defined by the surfaces 92 and 94 ofthe bracket and surface 15 of the shell, as best seen in FIG. 4, thenshoving the clip downwardly along surface 15 so that feet 110 passthrough these spaces. During this downward insertion movement, the upperedge of bracket 70 engages bowed portion 108 of each leg and cams thesame toward surface 15, resilient legs 102 and v 104- yieldably flexingand resisting this flattening deflection until portions 108 have clearedthe bracket, whereupon portions 108 spring back to their position shownin FIG. 3. When the clip is thus fully inserted, straight portions 106of the legs are pressed firmly against surfaces 92 and 94 of bracket 70by the stresses developed in the deflection of feet 110 of the legstoward bight 100, thereby securely retaining clip 72 in the positionshown in FIGS. 3 and with bight 100 resting on the upper edge of bracket70 and encircling and closely embracing the side of tube 40 disposedremote from surface 15. Clip 72 thus clamps tube 40 snugly againstbracket 70, but due to the resilient nature of clip 72 a very slightdeflection (in the order of a few thousandths of an inch) of the upperend 48 of tube 40 (to the left in the plane of the drawing as viewed inFIG. 3) can occur, clip 72 yielding and bending slightly to permit suchdeflection while resisting the same.

The assembly of compressor is completed by mounting motor compressorunit 22 on its spring suspension structure in casing 14, and thenconnecting the outlet end 44 of discharge tube 38 to the inlet end 48tube 40 as described previously. Due to the disposition of the upperedge 96 of tube 40 above flange 18, the junction 50 of these tubes isreadily accessible for the silver soldering operation. After thisconnection is made, the upper casing 16 is assembled on casing 14 andflanges 18 and 20 welded together to provide a hermetically sealedjoint.

From the foregoing description, it will now be apparent that thedischarge-connector tube construction of the present invention, and inparticular bracket 70 and spring clip 72, provides a simple, low costassembly and mounting arrangement which eliminates the necessity ofusing the prior art arrangement of silver soldering the dischargeconnector tube 40 to a bracket on the casing. In addition, it has beenfound that spring clip 72 overcomes the problem of the prior art silversoldered joint (between tube 40 and a casing bracket) breaking as aresult of the stress imposed on this joint when unit 22 was subjected tosevere vibration within and relative to housing 12, as during shipment.With clip 72, some of this stress is taken up in the clip 72 and bracket70 and the remainder is distributed along tube 40 and tube 38 because ofthe small but significant deflection permitted tube 40 in the vicinityof bracket 70 by clip 72. This deflection may only be in the order of afew thousandths of an inch, but this has been found to be sufficient toreduce the stress concentrations at this point to overcome the problemof failure of the tube intermediate support structure. However,sufficient support remains, and deflection of the interconnection oftubes 38, 40 is sufliciently limited by clip 72, so that no unnduestress is imposed on either joint or joint 60.

We claim:

1. In a compressor having a motor-compressor unit resiliently suspendedwithin a hermetic housing, the improvement comprising a discharge tubehaving an inlet at one end thereof connected to an outlet of saidcompressor unit, said discharge tube extending within said housingspaced from said unit and said housing and having an outlet at the endthereof opposite said inlet end, a discharge connector tube mounted onand extending through a wall of said housing and having an inlet endconnected to said outlet end of said discharge tube at a point withinsaid housing spaced from said wall thereof and support means secured tosaid housing and including a wire retainer having a bight portion atleast partially embracing one of said tubes and yieldably clamping saidtubes to said housing wall at a point between the connection of saiddischarge tube to said unit and the mounting of said connector tube onsaid wall.

2. In a compressor having a motor-compressor unit resiliently suspendedwithin a hermetic housing, the impnovement comprising a discharge tubehaving an inlet at one end thereof connected to an outlet of saidcompressor unit, said discharge tube extending within said housingspaced from said unit and said housing and having an outlet at the endthereof opposite said inlet end, a discharge connector tube mounted onand extending through a wall of said housing and having an inlet endconnected to said outlet end of said discharge tube at a point withinsaid housing spaced from said wall thereof and support means yieldablyclamping said tubes to said housing wall at a point between theconnection of said discharge tube to said unit and the mounting of saidconnector tube on said wall, said support means comprising a bracketdisposed between said wall and said tubes, said bracket being fixed tosaid wall and having a portion spaced inwardly of said housing away fromsaid wall, and a retainer having a first portion inserted in the spacebetween said bracket portion and said wall and a second portionextending about and embracing one of said tubes to yieldably secure saidone tube against said bracket.

3. In a compressor having a motor-compressor unit resiliently suspendedwithin a hermetic housing, the improvement comprising a discharge tubehaving an inlet at one end thereof connected to an outlet of saidcompressor unit, said discharge tube extending within said housingspaced from said unit and said housing and having an outlet at the endthereof opposite said inlet end, a

discharge connector tube mounted on and extending through a wall of saidhousing and having an inlet end connected to said outlet end of saiddischarge tube at a point within said housing spaced from said Wallthereof and support means yieldably clamping said tubes to said housingwall at a point between the connection of said discharge tube to saidunit and the mounting of said connector tube on said wall, said supportmeans comprising a corrugated metal-bracket having a center portion witha convex surface facing said wall and a concave surface opposite saidconvex surface, two crowns flanking said center portion, each of saidcrowns having a concave surface facing said wall, and two extremitiesfixed to said wall, one of said tubes nesting in said concave centerportion surface of said bracket, and a resilient retainer having acenter U-shaped bight portion embracing said one tube and two legs withone of said legs dependent from one end of said bight portion and theother leg from the other end of the bight portion, one leg beinginserted in the space between one of said crowns and the adjacentsurface of said wall and the other leg in the space between the othercrown and said wall.

4. The compressor set forth in claim 3 wherein said retainer comprises aspring steel wire and wherein each of said legs has a straight portionextending at right angles to bight portion a distance about equal to thedimension of said bracket parallel to said connector tube, said leg thenbeing curved inwardly of said housing away from said wall and thencurved outwardly of said housing toward said wall and terminating in arounded foot portion bearing slidably against said wall, said springwire being stressed when so mounted.

'5. The compressor set forth in claim 4 wherein said tubes runvertically at said interconnection therebetween and said spring retainerlegs are inserted downwardly into said bracket spaces.

6. In a compressor having a motor-compressor unit resiliently suspendedwithin a hermetic housing, the improvement comprising a discharge tubehaving an inlet at one end thereof connected to an outlet of saidcompressor unit, said discharge tube extending within said housingspaced from said unit and said housing and having an outlet at the endthereof opposite said inlet end, a discharge connector tube mounted onand extending through a wall of said housing and having an inlet endconnected to said outlet end of said discharge tube at a point withinsaid housing spaced from said wall thereof and support means yieldablyclamping said tubes to said housing wall at a point between theconnection of said discharge tube to said unit and the mounting of saidconnector tube on said wall, said housing having upper and lower casingsjoined at a circumferential seam and said connector tube being mountedin said lower casing and extending therethrough at a point spaced belowsaid support means, said support means comprising a retainer and abracket supporting said retainer with said bracket being disposed onsaid lower casing near said seam, said interconnection of said tubesbeing above said bracket near said seam.

7. The compressor set forth in claim 6 wherein said retainer clamps saidtube against said bracket and said retainer has limite dresilientyielding movement relative to said bracket and housing to permit slightflexing of said tubes in the vicinity of said tubes interconnectionrelative to the through-connection of said connector tube with saidcasing 8. The compressor as set forth in claim 7 wherein said connectortube is silver soldered to said lower casing at said through-connectiontherebetween.

References Cited UNITED STATES PATENTS 2,108,347 2/ 1938 Quarnstrom248-54 XR 2,842,218 7/1958 Bradbury 248-54 XR 3,082,939 3/1963 Warner230-235 ROBERT M. WALKER, Primary Examiner US. Cl. X.R.

